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Sun Aug 17, 2014 6:59 am

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Ok, so I searched, and Searched for Solar Info but now I'm even more confused.

1st off there's the Solar Panel Choices, and Size. This one seems that the 100watt is the panel size of choice. Although mounting also seems to be a dilemma.

2nd. There's the Solar Charge Controller. Ok, found many choices.

3rd. There's the Deep cycle Battery.. Now although this seems to be an easy answer I've found this to be one of the most difficult choices. There's the cheap WallyMart Deepclycles, and there's the Good expensive DeepCycles guess there's a difference, or I would hope so?

3-B.. Would be the Battery Maintainer required to keep that Deep Cycle up to snuff when not in use.

First off I realize that I'll have to size my system for the usage and appliances that I'm looking to power, but for now I'm truly trying to get a better handle on the big picture. Panel, Charger, Battery, and Battery maintainer for winter storage etc.

Things I do know for sure are that I only want to give up space for 1 solar Panel, and 1 good Deepcycle battery.

So here's my difficulty. :?

I noticed that a good Deep Cycle say 125-155 ah Battery could cost $300+
Noticed that brands like Trojan are among the top rated. But in there specs they say that they should be charged at around 15 CHARGING VOLTAGE: 14.7V RECOMMENDED: @ 15Amp's

So that kinds of blows my thoughts that deepcycle batteries should be slowly charged and maintained after reaching full charge at about 2 amps.

Also, another confusing item, is that most charge controllers for our small campers are only 10a, and will pass maybe 13 Volts charge, but a 100W solar panels can only produce maybe 7amps max, and around 18V in full Sun, with no clouds, or any shadows etc. Or at lease that is what I've seen on a few different friends Solar setups. Strange that the Panel is producing say 18V, but the controller is only passing 12-13Volts and varied amps of say 5 average.

It's also amazing when you monitor these setups with a Volt Meter and watch how the inbound voltage produced by the panel varies up and down with passing clouds etc. It really is much more sensitive then one would think. Now I know why some post and stress that you need full sun. Dang that's not always possible

I understand that 12gauge wire should be used, and wire run lengths should be kept manual.

So, how can a 100W Solar Panel that only produces maybe 7w max recharge or maintain a 100+ah Battery if the manufacture wants 15amps?
Everyday is not always a Sunny one, with good Rays?
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Sun Aug 17, 2014 1:24 pm

Yes, most car battery systems (house or starter) are not optimized for maximum charge capacity and usually charge below the battery manufacture's recommendations.

The controller needs to convert from the panel voltage to system voltage. Your system is 12 V so that's the kind of controller you need. You don't necessarily need double your capacity but you probably do what to capture as close to 100% of your panel output as you can. It's the most expensive part of the system.

Bigger wire and shorter runs are best.

The battery needs to fill up 15-30 amp-hours (how ever much you used), at 7 amps it takes more time than a 90 amp alternator.

When charging, the internal voltage of the battery goes up as it is charged. When it goes up the, amps it can draw goes down - eventually reaching nearly zero. To increase the battery's capacity, you hold the charge a few tenths of a volt above the battery level and you do it for several hours (following the manufacturer's recommendations). That's how you get the last 15-20% capacity of of the battery.

That over voltage time is where the hydrogen is produced, that is why the battery should be vented. For every two hydrogen atom that is vented you use up a water molecule so you need to check your battery's water regularly. The leftover oxygen molecule combines (oxidizes) what ever stray atoms so you need to use distilled water every time and your battery may not last as long.

Sun Aug 17, 2014 1:45 pm

I know first hand how confusing this can be.

I have lots of videos on YouTube about this. I will be doing some on putting solar on my westy but they are a ways out.

OBXSOLWIND is my YouTube channel

Hope it helps..

Sun Aug 17, 2014 3:52 pm

WestyDreamer........ I'm with you!

I understand simple electronics but when I venture into the solar array with multiple choices, price points, need configuration, etc.......
I just walk away.

I'm no where near ready to purchase but I fear that with the rapid advances in and changes in the technology that what I purchase today will be antiquated and half the price tomorrow!

Not unlike computers were in the past decade or so.

Someone, sell me a quality and affordable kit. Hold my hand, pat me on the head and say all will be well.........

Dave

Sun Aug 17, 2014 4:38 pm

It really depends how often you will run your batteries down and what you need to power. If you are starting out learning about solar I'd suggest reading through http://handybobsolar.wordpress.com/ website.

Solar isn't that difficult once you understand the various pieces and get an idea of what you need. I'm full timing in my Van on a long road trip and I run 200w of panels on my roof & 2x type 31 AGM deep cycles. This works fine in the Mid & south west or the southern east coast, but I'd be screwed in the PNW. Meaning it also depends where you are.

With that I keep all my electronics charged, run a 12v fridge 24/7 as well as my lights for night. I also run an inverter from time to time to power various things.

I do like solar, but unless you are doing a lot of boondocking as I do, then you may be able to get away with just a second battery charged by the van. First thing you need to do is really think about how much power you really need.

edit... also on the deep cycles.. I bought my type 31's which are AGM's from Sam's Club. They are labeled by Duracell but made by another battery company that has a good rep. {can't think of the name} They are probably the most affordable AGM's and I've had great luck with them so far. I'd buy them again.

Sun Aug 17, 2014 5:45 pm

Dear WestyDreamer,
You are overthinking this.

You certainly will read all kinds of stuff regarding solar..
But the facts remain.. it needn't be complicated.

1 solar panel..
1 deep cycle battery..
I charge controller..

.. and you are in business.

I don't think you have to get it perfect on a first install.
Buy the basic stuff.. hook it all up.. and see how it does for your needs.
Adjust to fit needs.

Many of us lived for years with no solar.. and a simple sealed lead-acid 85-110amp/hr deep cycle can keep up for several days.. so long as you aren't powering a bunch of home appliances thru an invertor... you'll be fine. Forget the AGMs and the MPPTs... just go basic, save some dollars, and see if its for you.

A loose panel also allows moving it to sunny spots.. since not all camp spots are in good sun. You really only need a few hrs a day.. so long as your battery bank is adequate and you don't go all home theater in your consumption.

If you see your not getting adequate charge? Then hop in your van and go to the store and get some M&Ms or something.. Voila.. batteries charged!

There are LOTS of primers on-line for solar basics.. I recommend visiting marine and RV sites.. and above all KISS! (at least in the beginning.)

Mon Aug 18, 2014 7:03 am

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I currently have no solar.

My Campers setup consist of the following DC Power Needs.

Truck fridge, some LED lighting, occasional radio, and in chilly weather a Propex Heater.

I currently have a cheap WallyFart 100ah Deepcycle battery that when used depending on devices used, I can get about 1&1/2 - 2 days of use from the el-cheapo 100ah battery.

I believe that my weak link is power needs verse Battery reserves.
So what I'm looking to do is extend my reserve battery needs.

I do not want to give up space for more then 1 Battery.
But would be open to updating the current 100ah Battery with a Good 125-155ah Battery.

But my confusion comes from manufactures like VMAX Batteries who's specs state that there battery recharge volts should be approx. 14V and 15amps.

Also most solar panel that can fit on our campers can only produce 7amps of which only approx 4-5 is pushed into the battery in full clear sky sun. And much of that is intermittently as the suns brightness comes and goes as does the amps.

The math just doesn't add up to the VMAX specs.
Thefolowing is from VMAX's spec Web Page..
"CHARGING VOLTAGE: 14.7V RECOMMENDED: 15A, 14.5V CHARGER: SMART/MICROPROCESSOR CONTROLLED CHARGER"
.

Mon Aug 18, 2014 7:14 am

I have used "el cheapo" lead acid deep cycle batteries for yrs on my sailboats and in my vans... including a solo sail to Hawaii of 15 days, running an autopilot for hrs on end.

Personally I think AGMs are over-rated.. They are expensive... and are easy to damage (shortened life) with inconsistent charging. They sometimes complain when charged in a system that includes a lead-acid starter battery.

An el cheapo can be trickled charged all day long with very little loss in cycles.
To appease the recommendations on your's, simply plug it into a regular charger (in your garage) once in awhile and take it to full.. at the recommended 14.7v/15A.. Also keep in mind that your alternator puts out close to that when you are driving.

For use while camping.. the trickle at 13.x volts off a typical solar controller will work fine for the duration of your stay.

Tue Aug 19, 2014 3:44 am

I would suggest that you get the biggest of everything that you can afford. Bigger is better and Quicker to
recharge your batteries. A 15 or 30 amp CC and 100 watts or more panel and a couple of hundred AH battery(s)
and you should be in business.